ACIP: Don't broaden smallpox vaccination program now

Jun 20, 2003 (CIDRAP News) – Because of the risk of heart inflammation, the Advisory Committee on Immunization Practices (ACIP) recommended yesterday that the federal smallpox immunization program not expand now beyond smallpox response teams to the larger population of health workers and emergency responders.

"The ACIP feels it is unwise to expand beyond the current, ACIP pre-event smallpox vaccination recommendations," the committee said in a draft recommendation adopted at a meeting in Atlanta. "ACIP is concerned about a new and unanticipated safety concern, i.e. myo/percarditis, whose extent and severity, particularly of long term sequelae, are not yet known." However, immunizations for smallpox response teams of public health and healthcare workers should continue, the resolution states.

Twenty-one cases of myocarditis and/or pericarditis had occurred among 36,217 civilian smallpox vaccinees as of May 9, according to the Centers for Disease Control and Prevention (CDC). In addition, 27 cases had occurred among more than 430,000 people in the military smallpox vaccination program by May 16, according to the Department of Defense (DoD).

The ACIP's draft recommendation, a copy of which was provided by the CDC, does not suggest conditions for the expansion of the immunization program or indicate when that should happen. The wording of the recommendation may still change before it becomes official, CDC spokesman Curtis Allen told CIDRAP News. The ACIP is a 15-member panel of experts that advises the CDC on immunization issues.

In a news briefing yesterday, CDC Director Julie Gerberding said the CDC and Department of Health and Human Services (HHS) will consider the ACIP's recommendation, but she expressed a determination to continue to improve the nation's preparedness for a smallpox outbreak. The ACIP recommendation had not been formally announced at the time of the briefing.

"When we get advice from the ACIP, we will be respectfully considering it, and I'm sure the secretary [of HHS] will be weighing that advice in conjunction with the other input he receives," Gerberding said. "But nothing in any of this will change the overarching goal, and the overarching goal is that our nation is prepared to protect our citizens from a smallpox attack."

Later Gerberding added, "My metric in all of this is, let's get prepared. Now, the concept of expansion or staging or pausing or not pausing is not something that has been part of my expectation for the smallpox preparedness program."

As of Jun 13, 37,608 civilian health workers had received smallpox shots in the program launched last January, according to the CDC. Plans originally called for vaccinating up to 450,000 health workers for smallpox response teams and then expanding the program to millions of other health workers and emergency responders, such as police and firefighters. The tepid response to the voluntary program has been blamed on concerns about vaccination complications and compensation, a perceived decrease in the smallpox threat after the war in Iraq, and the SARS outbreak.

The ACIP statement more or less echoes a recent recommendation from the Institute of Medicine's Committee on Smallpox Vaccination Program Implementation. That group, which also advises the CDC, recommended in late May that the CDC pause to evaluate safety issues and assess which other groups should be vaccinated before expanding the program beyond the smallpox response teams.

While advising against a major expansion of the immunization program, the ACIP said smallpox preparedness efforts should continue. The resolution says, "It is critical for smallpox preparedness planning, within the context of broader terrorism and emergency response planning, to continue at the federal, state, and local levels." Preparedness planning should include surveillance for smallpox cases, provisions for care of patients, and plans for mass vaccination, the resolution says.

At the news briefing, Gerberding insisted that smallpox is still a threat and stressed that smallpox preparedness requires much more than vaccinations. "It's very tempting to conclude that somehow the smallpox risk has miraculously evaporated, and that's just simply not true," she said.

"The fact that we have almost 40,000 people vaccinated is a tremendous step forward compared to where we were just six months ago," she said. However, she continued, "This is not about a number." Preparedness includes the ability to detect smallpox cases and report them to local health officials, the ability to isolate patients and quarantine exposed people appropriately, and the ability to vaccinate the population quickly, she said.

Later she elaborated, "We don't need people immunized in every hospital in the country. Some regions may decide that there is going to be sort of a referral hospital, just as we did with SARS, where there may be one facility that will be the place where the smallpox patients will be taken care of."

She also said the experience with the SARS and monkeypox outbreaks—particularly with regard to using isolation and quarantine authorities—has improved preparedness for smallpox.

Gerberding acknowledged that the heart inflammation cases have been an unexpected side effect of smallpox vaccine but said the overall safety record has exceeded expectations. "The news from the Department of Defense, where they have had far more people vaccinated, is that overall the safety of the vaccine program is better than we had initially expected," she said.

The DoD's safety report lists 36 mild cases of generalized vaccinia but no severe reactions such as eczema vaccinatum or progressive vaccinia. No deaths have been attributed to the vaccine, though one 55-year-old solider with preexisting heart disease died of a heart attack 5 days after his smallpox shot. In the civilian program, nine vaccinees suffered heart attacks or angina within weeks after their shot, and two of them died.

"The best epidemiological information indicates that those heart attacks are most likely a coincidence and not directly associated with the vaccine at all," Gerberding said.